MISSOULA — Our week of inversion weather is about to come to an end as an incoming winter system will bring major changes.
Forecast models are not very clear, or in agreement, with this system in general. However, one thing that looks consistent is the timing of the storm. Most models show the wintry mix arriving tomorrow, picking up around the AM rush hour.
When the warmer air and moist air collides with our current cold pools tomorrow, then it will be more clear as to what we can expect through the weekend.
The local National Weather Service office has issued a Winter Storm Watch that begins tomorrow. Generally, Winter Storm Watches turn into Winter Storm Warnings but the uncertainty with this forecast is still high.
The ranges that the NWS office gave for snow totals are listed incredibly far apart:
Kootenai/Cabinet Region-West Glacier Region-Flathead/Mission Valleys- ...WINTER STORM WATCH IN EFFECT FROM FRIDAY MORNING THROUGH MONDAY AFTERNOON... * WHAT...Heavy mixed precipitation possible. Chance of moderate to major impacts from snow or ice is at least 50 percent. Total snow accumulations between 4 and 22 inches and ice accumulations aroundone tenth of an inch possible.
Northern Clearwater Mountains-Southern Clearwater Mountains-Lower Clark Fork Region-Bitterroot/Sapphire Mountains-Potomac/Seeley Lake Region- ...WINTER STORM WATCH IN EFFECT FROM FRIDAY AFTERNOON THROUGH MONDAY AFTERNOON... * WHAT...Heavy snow possible. Chance of moderate to major impacts from snow or ice is at least 50 percent. Total snow accumulations between 4 and 26 inches and ice accumulations around one tenth of an inch possible.
Missoula/Bitterroot Valleys- ...WINTER STORM WATCH IN EFFECT FROM FRIDAY EVENING THROUGH MONDAY AFTERNOON... * WHAT...Heavy mixed precipitation possible. Chance of moderate to major impacts from snow or ice is at least 50 percent. Total snow accumulations between 1 and 8 inches and ice accumulations around a tenth of an inch possible.
As you can see, these ranges are for the long-term snow event and also display the level of uncertainty with forecasting this system.
One of the main impacts possible is some freezing rain Friday night, which would be then covered by snow Saturday morning. So, roads could be rough off and on until Tuesday next week.
Following the moisture event, we then expect another blast of arctic air early next week. All in all, we recommend gearing up for at least some winter weather.
